scholarly journals Multiple Geographical Origins of Environmental Sex Determination enhanced the diversification of Darwin’s Favourite Orchids

2017 ◽  
Author(s):  
Oscar Alejandro Pérez-Escobar ◽  
Guillaume Chomicki ◽  
Fabien L. Condamine ◽  
Jurriaan M. de Vos ◽  
Aline C. Martins ◽  
...  
Keyword(s):  
Sex Determination ◽  
Mating Systems ◽  
Driving Forces ◽  
Environmental Cues ◽  
Sexual System ◽  
Environmental Sex Determination ◽  
Diversification Rates ◽  
Sexual Systems ◽  
Alternative Systems ◽  
Phylogenetic Framework

AbstractEnvironmental sex determination (ESD) – a change in sexual function during an individual life span driven by environmental cues – is an exceedingly rare sexual system among angiosperms. Because ESD can directly affect reproduction success, it could influence diversification rate as compared with lineages that have alternative mating systems. Here we test this hypothesis using a solid phylogenetic framework of Neotropical Catasetinae, the angiosperm lineage richest in taxa with ESD. We assess whether gains of ESD are associated with higher diversification rates compared to lineages with alternative systems while considering additional traits known to positively affect diversification rates in orchids. We found that ESD has evolved asynchronously three times during the last ~5 Myr. Lineages with ESD have consistently higher diversification rates than related lineages with other sexual systems. Habitat fragmentation due to mega-wetlands extinction, and climate instability are suggested as the driving forces for ESD evolution.

Do the Offspring of Sex Reversals Have Higher Sensitivity to Environmental Perturbations?

2021 ◽  
pp. 1-14
Author(s):  
Francesc Piferrer ◽  
Dafni Anastasiadi
Keyword(s):  
Sex Determination ◽  
Molecular Mechanisms ◽  
Global Climate ◽  
Sex Reversal ◽  
Environmental Cues ◽  
Environmental Sex Determination ◽  
Future Studies ◽  
Genome Data ◽  
Environmental Perturbations ◽  
Higher Sensitivity

Sex determination systems in vertebrates vary along a continuum from genetic (GSD) to environmental sex determination (ESD). Individuals that show a sexual phenotype opposite to their genotypic sex are called sex reversals. Aside from genetic elements, temperature, sex steroids, and exogenous chemicals are common factors triggering sex reversal, a phenomenon that may occur even in strict GSD species. In this paper, we review the literature on instances of sex reversal in fish, amphibians, reptiles, birds, and mammals. We focus on the offspring of sex-reversed parents in the instances that they can be produced, and show that in all cases studied the offspring of these sex-reversed parents exhibit a higher sensitivity to environmental perturbations than the offspring of non-sex-reversed parents. We suggest that the inheritance of this sensitivity, aside from possible genetic factors, is likely to be mediated by epigenetic mechanisms such as DNA methylation, since these mechanisms are responsive to environmental cues, and epigenetic modifications can be transmitted to the subsequent generations. Species with a chromosomal GSD system with environmental sensitivity and availability of genetic sex markers should be employed to further test whether offspring of sex-reversed parents have greater sensitivity to environmental perturbations. Future studies could also benefit from detailed whole-genome data in order to elucidate the underlying molecular mechanisms. Finally, we discuss the consequences of such higher sensitivity in the context of global climate change.

Environmental Sex Determination Mechanisms in Reptiles

2013 ◽  
Vol 7 (1-3) ◽  
pp. 95-103 ◽  
Author(s):  
H. Merchant-Larios ◽  
V. Díaz-Hernández
Keyword(s):  
Sex Determination ◽  
Environmental Sex Determination ◽  
Sex Determination Mechanisms

scholarly journals Outbreeding and inbreeding strategies in herbaceous-shrubby communities in the Venezuelan Gran Sabana Plateau

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Nelson Ramírez ◽  
Omaira Hokche
Keyword(s):  
Plant Species ◽  
Carbon Metabolism ◽  
Life Form ◽  
Sex Expression ◽  
Perennial Herb ◽  
Sexual System ◽  
Dioecious Species ◽  
Successional Stage ◽  
Sexual Systems ◽  
Perennial Herbs

Abstract Breeding system, sexual system, temporal variation in sex expression and herkogamy were evaluated in seven herbaceous-shrubby communities from the Gran Sabana Plateau, Venezuela. This analysis was conducted considering the life form, substrate type, succulence, carbon metabolism, nutritional relation, successional stage, pollination system specificity and endemism of plant species. Of the 348 plant species studied, 73.8 % were hermaphrodite, 16.9 % were monoecious and 9.2 % were dioecious. Plant sexual systems such as dichogamy and herkogamy were associated with life form, nutritional relations, carbon metabolism and pollination systems. Most species were adichogamous, followed by protandrous and protogynous. Protandry was high for perennial herbs, annual herbs and trees, and protogyny was most frequent in perennial herbs. Protandrous and protogynous species were frequently anemophilous. Herkogamy was higher than non-herkogamy. Herkogamy was higher for trees, shrubs and liana; higher in monophilous and lower in anemophilous species. Most of the hermaphrodites were herkogamous and adichogamous species. In contrast, monoecy were commonly perennial herb and dichogamous species and frequently associated with anemophily. Dioecious species were trees and shrubs and with polyphilous pollination. Dioecy was the most frequent sexual system for endemic species. Hermaphrodite species were similarly distributed across plant communities. Monoecy was slightly higher for savanna and fallow than the other communities, and dioecy was higher for shrublands and secondary bushland. Most plant species were non-agamospermous, non-spontaneous self-pollinated and xenogamous. Partially self-incompatible dominated, followed by self-incompatible, partially cross-incompatible and the lowest frequency corresponded to cross-incompatible species. All these results are discussed in the context of evolutionary and ecological trends.

scholarly journals Multiple Geographical Origins of Environmental Sex Determination enhanced the diversification of Darwin’s Favourite Orchids

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Oscar Alejandro Pérez-Escobar ◽  
Guillaume Chomicki ◽  
Fabien L. Condamine ◽  
Jurriaan M. de Vos ◽  
Aline C. Martins ◽  
...  
Keyword(s):  
Sex Determination ◽  
Environmental Sex Determination
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